Pressure feeds in a rotating shaft, located in a gearbox are known. For instance, DE 199 21 749 A1 describes pressure oil feed into a primary shaft of a variable speed transmission of a continuously variable automatic transmission. The primary shaft is located in the gearbox housing using a bearing. In the region of this bearing, there is a bore of the bearing that penetrates the wall of the housing in the gearbox housing. The bearing is fixed axially in the gearbox with a locking ring. To ensure constant pressure oil supply to the variable speed transmission, an electro-hydraulic control device is provided which is arranged vertically toward the bore of the bearing on the face of the gearbox and which at the same time covers the bore of the bearing in the gearbox. The supply of oil from the electro-hydraulic control device into an axial bore of the primary shaft takes place through a coupler system, in which two tubes fitted into one another are inserted oil-tight into the step bore of the electro-hydraulic device. Both the tubes project into the axial bore of the primary shaft by means of a sliding bearing. The outer tube is axially fixed to the electro-hydraulic control device through a retaining sheet. The inner tube does not have any axial locking.
A pressure feed for the variable speed shaft of a continuously variable transmission has been made known in DE 199 32 339 A1 submitted by the Applicant. According to this, the pressure oil supply from a hydraulic transmission control device takes place through an oil supply channel arranged in the gearbox and subsequently through an oil supply channel arranged in a gearbox cover into an axial step bore of the variable speed shaft. The variable speed shaft is positioned in the gearbox through at least one bearing and the bearing is placed in a corresponding bore of the bearing within the gearbox and the bearing is affixed axially in this bore using a retaining sheet. The bore of the bearing is constructed like a connecting bore, into which the variable speed shaft projects and the cover of the gearbox covers the bore. A tubular projection of the gearbox cover projects into the axial step bore of the variable speed shaft and is sealed against the rotating variable speed shaft by means of a rectangular piston ring. The pressure oil is led from a gearbox channel into a gearbox cover channel running parallel to the shaft. From there, it is then led to a bore in the gearbox cover which runs vertically toward the shaft and subsequently through an inner axial bore of the tubular projection of the cover to the variable speed shaft. A flat packing seals the oil supplying channels on the outer surface along the parting line between the gearbox and the gearbox cover.
The object of the current invention is to further develop a pressure feed from a hydraulic or pneumatic transmission control device into a gear shaft, particularly for applications where the loss in pressure from the hydraulic or the pneumatic control device to the shaft does not take place in the immediate vicinity of the shaft, considering the problems arising out of the proximity, particularly in case of high pressures.